Method of using oscillating assembly and exhaust system

ABSTRACT

A method of using an exhaust system includes activating an oscillating assembly connected to an exhaust line, wherein the oscillating assembly is configured to vibrate the exhaust line. The method further includes measuring a value indicating a flow of particles through the exhaust line. The method further includes comparing the value with a predetermined threshold value. The method further includes increasing a rate of vibration of the exhaust line in response to the value being below the predetermined threshold value.

PRIORITY CLAIM

The instant application is a divisional application of U.S. applicationSer. No. 15/478,672, filed Apr. 4, 2017, which is a non-provisionalapplication claiming priority to Provisional Application No. 62/427,647,filed Nov. 29, 2016, the entire contents of which are incorporated byreference herein.

BACKGROUND

Flow disruption sites in an exhaust system impede removal of gases andparticles from an upstream source of the exhaust system. Bends andconnectors in exhaust lines disrupt exhaust flow by slowing the movementof exhaust gases, which reduces pumping efficiency. Particulate mattersuspended or transported by the exhaust system tends to collect at flowdisruption sites in the exhaust system. Buildup of particulate matter inan exhaust line reduces an area of the exhaust line available forexhaust gases and particles to flow through the exhaust system. Buildupof particulate matter reduces pumping efficiency and leads to increasedmaintenance to manually remove buildup and maintain uninterruptedexhaust flow within desired specifications and consequently reducesoperating efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or decreased for clarity of discussion.

FIG. 1A is a cross-sectional view of an oscillating assembly, accordingto some embodiments.

FIG. 1B is a cross-sectional view of an oscillating element, accordingto some embodiments.

FIG. 2A is a graph of a relationship between a flow rate of gas andacceleration/velocity of an oscillating assembly, according to someembodiments.

FIG. 2B is a graph of a relationship between a pressure of gas andacceleration/velocity of an oscillating assembly, according to someembodiments.

FIG. 3 is a schematic view of an exhaust system, according to someembodiments.

FIG. 4 is a flowchart of a method of operating an exhaust system,according to some embodiments.

FIG. 5 is a block diagram of a controller for controlling an exhaustsystem, in accordance with some embodiments.

DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components, values, operations, materials,arrangements, or the like, are described below to simplify the presentdisclosure. These are, of course, merely examples and are not intendedto be limiting. Other components, values, operations, materials,arrangements, or the like, are contemplated. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Many exhaust systems handle exhaust streams that include particulatematter. In some instances, particulate matter builds up within theexhaust system, particularly at flow disruption sites. A flow disruptionleads to a decrease in flow velocity through the exhaust system. Flowvelocity through the exhaust system changes based on changes in exhaustline diameters, changes in bends in exhaust lines, and changes atconnectors between exhaust lines. Decreased flow velocity results inparticles, which are suspended in the exhaust stream, contacting andadhering to interior walls of the exhaust system lines, or otherparticles adhered to the interior walls, with greater frequency thanwith nominal flows of the exhaust system. For example, at an entrance ofthe exhaust system, a diameter of the exhaust line tends to be larger.The larger diameter of the exhaust line reduces a flow velocity withinthe exhaust line in comparison with smaller diameter exhaust lines.Nominal flow velocity overcomes frictional forces that adhere particlesto interior walls of exhaust lines or other particles; however, wherethe flow velocity is reduced, a risk of particles adhering to interiorwalls of the exhaust line increases. Adhering particles create acompound effect that, once begun, promotes further particle adhesionwhere particles have begun to collect in an exhaust line.

Over time, particle buildup in the exhaust system reduces the flowvelocity for the exhaust system. Reduced flow velocity corresponds toreduced particle removal efficiency. In some instances, reduced flowvelocity and reduced particle removal efficiency contribute tocontamination of semiconductor wafers or other materials that arehandled by manufacturing equipment. In some instances, reduced particleremoval efficiency raises the frequency of preventive maintenance.Maintenance of the exhaust system to remove the adhered particles fromthe exhaust lines restores clogged systems to nominal functionality.However, maintenance includes removing a tool connected to the exhaustsystem from normal operation during performance of the maintenanceprocedure. Maintenance due to particulate contamination reducesavailability and productivity of manufacturing equipment. In someembodiments, the interior wall of an exhaust line is a coated surface.The coating on the coated surface includes, in some embodiments, atleast one of polytetrafluoroethylene (PTFE), polyurethane,polypropylene, nylon, or another coating with a coefficient of staticfriction that is smaller than the coefficient of static friction ofstainless steel.

Agitating particles adhered to the interior wall of an exhaust linehelps the flow within the exhaust line to remove particles from theinterior wall, thereby reducing particle buildup within the exhaustline. The particles within the exhaust line are agitated by inducingvibrations of the exhaust line. The movement of the exhaust line istransferred to the particles and pushes the particles back toward acenter of the exhaust line where a flow velocity is highest. Byagitating particles within the exhaust line, particle buildup within theexhaust line is slowed. As a result, preventive maintenance schedulesare extended and manufacturing tools attached to the exhaust line remainin operation for a greater period of time and overall productioncapacity is increased.

FIG. 1A is a cross-sectional view of an oscillating assembly 100 inaccordance with some embodiments. Oscillating assembly 100 includes anoscillating element 110 connected to a securing device 120 with a gasket130 between the oscillating element 110 and the securing device 120.Securing device 120 is configured to attach oscillating assembly 100 toan exhaust line 150 of an exhaust system. One of ordinary skill in theart would recognize that exhaust line 150 is labeled in FIG. 1A forclarity and is not part of oscillating assembly 100. Oscillating element110 is configured to create an oscillating movement which is transferredto exhaust line 150 through securing device 120.

Oscillating element 110 includes an inlet 112 configured to receive aflow of gas and an outlet 114 configured to output the gas. Inlet 112and outlet 114 are both connected to a chamber 116. A moveable element115 is located within chamber 116. A gas passing from inlet 112 tooutlet 114 through chamber 116 creates a flow path 118. The movement ofthe gas along flow path 118 causes moveable element 115 to move withinchamber 116. By controlling a flow rate and/or a pressure of gas, themovement of moveable element 115 creates an oscillating motion byoscillating element 110.

In some embodiments, oscillating element 110 has a differentconfiguration. For example, in some embodiments, oscillating elementincludes a motor configured to rotate an element having an unbalancedweight. The rotation of the unbalanced weight results in an oscillatingmotion of oscillating element 110. In some embodiments, moveable element115 is omitted and a velocity of the gas through chamber 116 iscontrolled to create an oscillating motion.

Oscillating element 110 includes a strong and resilient material whichhas a sufficient mechanical strength to resist damage by movement ofmoveable element 115. As a weight of oscillating element 110 increasesan amount of kinetic energy generated by the oscillating motionincreases; however, the velocity of the gas through chamber 116 isincreased in order to create the oscillating motion. In someembodiments, oscillating element 110 includes stainless steel, iron,aluminum or another suitable material.

Inlet 112 is configured to receive the flow of gas. In some embodiments,inlet 112 includes a threaded opening to receive a conduit forconducting the flow of gas. In some embodiments, inlet 112 includes acheck valve to prevent a flow of gas in a direction out of chamber 116by way of inlet 112. In some embodiments, inlet 112 includes acontrollable valve configured to selectively permit the flow of gas toenter chamber 116. As a diameter D1 of inlet 112 increases, a velocityof gas along flow path 118 decreases. A higher velocity of gas alongflow path 118 increases a speed of moveable element 115 and increases afrequency of the oscillating motion. In some embodiments, diameter D1 ofinlet 112 ranges from about 1 centimeter (cm) to about 5 cm.

Outlet 114 is configured to output the flow of gas. In some embodiments,outlet 114 includes a threaded opening to receive a conduit forconducting the flow of gas. In some embodiments, outlet 114 includes acheck valve to prevent a flow of gas in a direction into chamber 116 byway of outlet 114. In some embodiments, outlet 114 includes acontrollable valve configured to selectively permit the flow of gas toexit chamber 116. As a diameter D2 of outlet 114 increases, a velocityof gas along flow path 118 decreases. In some embodiments, diameter D2of outlet 114 ranges from about 1 cm to about 5 cm. In some embodiments,outlet 114 has a same diameter as inlet 112. In some embodiments, outlet114 has a different diameter from inlet 112. In some embodiments, inlet112 has a larger diameter than outlet 114. In some embodiments, inlet112 has a smaller diameter than outlet 114.

Moveable element 115 includes a ball bearing. A material of moveableelement 115 is sufficiently strong and resilient to resist damage duringmovement within chamber 116. As a weight of moveable element 115increases an amount of kinetic energy generated by movement of moveableelement 115 within chamber 116 increases; however, the velocity of thegas through chamber 116 is increased in order to move moveable element115. In some embodiments, a weight of moveable element 115 ranges fromabout 0.005 kilograms (kg) to about 0.5 kg. In some embodiments,moveable element 115 includes stainless steel, iron, aluminum or anothersuitable material. In some embodiments, a material of oscillatingelement 110 and moveable element 115 is a same material. In someembodiments, a material of oscillating element 110 is different from amaterial of moveable element 115. In some embodiments, oscillatingelement 110 includes aluminum and moveable element 115 includesstainless steel.

Moveable element 115 has a spherical shape. The spherical shape helps topermit moveable element 115 to move within chamber 116 with minimaldamage to interior walls of chamber 116. The spherical shape of moveableelement 115 also helps to facilitate a more uniform oscillating motion.In some embodiments, moveable element 115 has a diameter ranging fromabout 0.5 cm to about 1 cm. A greater diameter requires a biggeroscillating element 110, thereby increasing a manufacturing cost withouta significant improvement in functionality, in some instances. A smallerdiameter provides insufficient vibration to agitate particles within theexhaust line, in some instances. In some embodiments, moveable element115 has a different shape in order to create a more turbulentoscillating motion. A turbulent oscillating motion will help increaseagitation of particles within exhaust line 150, in some instances. Insome embodiments, moveable element 115 is polygonal prism, egg-shaped,freeform-shaped or another suitable shape.

Chamber 116 is an opening within oscillating element 110 to permitmoveable element 115 to move and create the oscillating motion. Chamber116 is circular. The circular shape of chamber 116 helps to provide asmooth flow path 118 in order to create a more uniform oscillatingmotion. In some embodiments, chamber 116 has a different shape in orderto create a more turbulent oscillating motion. In some embodiments,chamber 116 is polygonal, oval or freeform-shaped. In some embodimentswhich omit moveable element 115, chamber 116 is shaped to create theoscillating motion based solely on the gas travelling along flow path118. Chamber 116 is centered in oscillating element 110. In someembodiments, chamber 116 is offset from a center of oscillating element110 in order to increase an amplitude of the oscillating motion.

Flow path 118 determines a direction that moveable element 115 travelswithin chamber 116. Flow path 118 is determined based on a location ofinlet 112 and outlet 114 as well as a shape of chamber 116.

Securing device 120 attaches oscillating element 110 to exhaust line150. Securing device 120 is a collar. In some embodiments, securingdevice 120 includes a magnet, a clamp, screws, rivets, springs, welding,adhesive or another suitable attachment mechanism. Securing device 120extends around an entire circumference of exhaust line 150. In someembodiments, securing device 120 extends around only a portion of thecircumference of exhaust line 150. Securing device 120 includes aplurality of contact points 122 which directly contact exhaust line 150.Contact points 122 transfer the oscillating motion from oscillatingelement 110 to exhaust line 150. In some embodiments, securing device120 includes aluminum, iron, steel or another suitable material.

Contact points 122 help to pass vibration generated from oscillatingelement 110. In some embodiments, contact points 122 help to reduce wearon exhaust line 150 during operation of oscillating assembly 100.Instead of the entirety of securing device 120 directly contactingexhaust line 150, a reduced area of exhaust line 150 is contacted bycontact points 122. This arrangement helps to reduce wear because duringoperation securing device 120 will move slightly with respect to exhaustline 150 causing the two structures to rub against one another. By usingcontact points 122, securing device 120 is able to be repositionedaround exhaust line 150 in order to change a location of the wearing onexhaust line 150. Contact points 122 include a softer material thanexhaust line 150 in order to reduce wear on exhaust line 150 duringoperation of oscillating assembly 100. In some embodiments, contactpoints 122 include aluminum, iron, steel or another suitable material.In some embodiments, contact points 122 have a same material as the restof securing device 120. In some embodiments, contact points 122 have adifferent material from the rest of securing device 120. In someembodiments, a useful life of oscillating assembly 100 is at least 1.5years. A longer useful life means that manufacturing costs are reduced.

In some embodiments, contact points 122 are integral with a rest ofsecuring device 120. In some embodiments, contact points 122 areremovable from the rest of securing device 120 in order to facilitatereplacement of contact points 122. In some embodiments, removablecontact points 122 are attached to the rest of securing device 120 byscrews, detents, adhesive or other suitable components.

Contact points 122 are evenly distributed around exhaust line 150. Insome embodiments, a length of contract points 122 ranges from about 0.5cm to about 1 cm. In some embodiments, a spacing between adjacentcontract points 122 ranges from about 0.5 cm to about 1 cm. In someembodiments, a spacing between two adjacent contact points 122 isdifferent from a spacing between two other adjacent contact points 122.

Gasket 130 helps to reduce wear on oscillating element 110 and securingdevice 120 during operation of oscillating assembly 100. Gasket 130includes a softer material than oscillating element 110 and securingdevice 120. In some embodiments, gasket 130 is connected to oscillatingelement 110 by screws extending through gasket 130 and connecting thesecuring device 120. In some embodiments, gasket 130 is attached tosecuring device 120 or oscillating element 110 by an adhesive.

FIG. 1B is a cross-sectional view of oscillating element 110 inaccordance with some embodiments. FIG. 1B is a larger view ofoscillating element in comparison with that provided in FIG. 1A. Anattachment opening 117 is more visible in FIG. 1B than FIG. 1A.Attachment opening 117 permits attaching elements, such as a screw, toextend through oscillating element 110 through gasket 130 (FIG. 1A) andinto securing device 120.

Oscillating element 110 has a width W ranging from about 7 cm to about16 cm. A height H of oscillating element 110 ranges from about 4 cm toabout 10 cm. A depth D of oscillating element 110 ranges from about 1.5cm to about 5.5 cm. As the dimensions of oscillating element 110increase, a mass of oscillating element also increases. The mass ofoscillating element 110 impacts an amount of kinematic energy created bythe oscillating motion.

FIG. 2A is a graph of a relationship between a flow rate of gas andacceleration/velocity of an oscillating assembly. In some embodimentswhere an applied pressure is controlled around 0.5 MPa, bothacceleration and velocity of oscillating assembly 100 are proportionalto a flow rate of the gas. In some embodiments, inlet 112 of oscillatingelement 110 is configured to receive the gas at a flow rate ranging fromabout 30 liters per minute (lpm) to about 50 lpm, and the accelerationranges from about 20 millimeters per second squared (mm/s²) to about 35mm/s². A greater flow increases a risk of wear of moveable element 115,in some instances. A smaller flow rate provides insufficient vibrationto agitate particles within the exhaust line, in some instances. Theflow rate of the gas determines the velocity of moveable element 115within chamber 116. Based on the mass of moveable element 115, a forceexerted by movement of moveable element 115 ranges from about 1×10⁻³Newtons (N) to about 1.75×10⁻³ N.

FIG. 2B is a graph of a relationship between a pressure of gas andacceleration/velocity of an oscillating assembly. In some embodimentswhere a flow rate is controlled around 35 lpm, both acceleration andvelocity of oscillating assembly 100 are proportional to a pressure ofthe gas in a range from 0.1 MPa to 0.3 MPa. When the pressure is greaterthan 0.3 MPa, both acceleration and velocity are saturated due to alimitation of the fixed flow rate.

FIG. 3 is a schematic view of an exhaust system 300 in accordance withsome embodiments. Exhaust system 300 includes a mixing box 310 connectedto an inlet 302. In some embodiments, exhaust system 300 is alsoreferred to as a local scrubber. A circulation device 306 is configuredto provide a pressure differential to move particles and fluids throughexhaust system 300. In at least one embodiment, circulation device 306is a turbine. A gas outlet 304 is connected to an outlet of circulationdevice 306. A by-pass line 320 is connected downstream of mixing box310. A controllable valve 325 is connected to by-pass line 320 tocontrol the flow of gas through by-pass line 320. A feedback path 322connects an external gas source 370 to an oscillating assembly 330. Gasfrom external gas source 370 is supplied to an oscillating element,e.g., oscillating element 110 (FIG. 1A), of oscillating assembly 330along feedback path 322. Oscillating assembly 330 is connected to anexhaust line downstream of by-pass line 320. In some embodiments,oscillating assembly 330 is connected to an exhaust line upstream ofby-pass line 320. In some embodiments, more than one oscillatingassembly 330 is connected to the exhaust line. For example, in at leastone embodiment, a first oscillating assembly 330A is positioned around afirst coupling element 312 under mixing box 310, and a secondoscillating assembly 330B is positioned around a second coupling element314 above a washing section. In some embodiments, exhaust system 300includes a vibration sensor 335. Vibration sensor 335 is configured todetect a vibration of oscillating assembly 330. In some embodiments,vibration sensor 335 is always attached to oscillating assembly 330 tomonitor oscillating assembly 330 in real-time. In some embodiments,vibration sensor 335 is activated only when exhaust system 300 isoperating. In some embodiments, vibration sensor 335 is attached tooscillating assembly 330 at a predetermined time interval, for example,every twelve hours. In some embodiments, vibration sensor 335 includes alaser guided sensor, an infrared sensor, a microwave motion sensor, anultrasonic motion sensor or another suitable sensor. In someembodiments, more than one vibration sensor 335 is used to detectmultiple oscillating assemblies.

An optional reactor 340 is configured to pyrolysize exhaust and/orparticulate matters. A first tank 350 is configured to provide a washingfluid to the exhaust line at washing fluid inlets 345, as indicated bybroken lines intersecting with the exhaust line. The washing fluid isused to flush exhaust and/or particles downward. First drain tank 350 isconfigured to receive particles and fluids from the exhaust line. Asecond drain tank 355 is selectively connected to first drain tank 350by a valve in order to remove fluids from exhaust system 300. In someembodiments, second tank 355 is configured to recycle purified washingfluids back into exhaust system 300 by a return pipe 360. External gassource 370 is configured to supply gas to feedback path 322 and reactor340. In some embodiments, gases to feedback path 322 and reactor 340 areseparately supplied by external gas source 370 and a backup external gassource (not shown).

Exhaust system 300 is configured to remove exhaust and/or particles froma manufacturing tool. In some embodiments, the manufacturing toolincludes a furnace, a lithography tool, a deposition chamber, aplanarization tool, an etching tool or another suitable manufacturingtool. By removing particles from the manufacturing tool, exhaust system300 helps to prevent contamination of a device being manufactured, e.g.,a semiconductor wafer, by the particles. Inlet 302 is configured toreceive an exhaust mixture from one or more manufacturing tools301(1)-301(n). For example, in some embodiments, inlet 302 is configuredto receive an exhaust mixture from a furnace and another exhaust mixturefrom a photolithography apparatus. The exhaust mixture includes gas(es)and particles. While only one inlet 302 is included in FIG. 3, one ofordinary skill in the art would understand that multiple inlets areincluded in some embodiments. The inlets are combined in mixing box 310.

Circulation device 306 is connected near gas outlet 304 of exhaustsystem 300 in order to provide a pressure differential through exhaustsystem 300 in order to move exhaust through exhaust system 300. In someembodiments, gas outlet 304 is connected to a general exhaust system(GEX), an acid exhaust system (SEX) or an ammonia exhaust system (AEX).In some embodiments, circulation device 306 includes a pump. In someembodiments, circulation device 306 includes a fan. In some embodiments,the pressure differential created by circulation device 306 iscontrollable to adjust a velocity of particles and fluid through exhaustsystem 300.

Mixing box 310 is configured to receive the particles and fluid frominlet 302, or from multiple inlets. In some embodiments, mixing box 310connects to a heating unit configured to keep fluids in a gaseous stateor a plasma-assisted unit configured to chemically break down theexhaust gas. For example, in at least one embodiment where the exhaustincludes ammonium chloride, a temperature of mixing box 310 is in arange from about 100 degrees Celsius to about 130 degrees Celsius toavoid the generation of solid-state ammonium chloride. A highertemperature increases a manufacturing cost without a significantimprovement in functionality, in some instances. A lower temperatureincreases a risk of generating more particles, in some instances. Insome embodiments, mixing box 310 is integral with the heating unit orthe plasma-assisted unit. Mixing box 310 helps to separate inlet 302from the pressure differential created by circulation device 306, whichcould negatively impact a manufacturing tool upstream along inlet 302.Mixing box 310 contains particles as well as fluids, such as gases,received from inlet 302.

In some embodiments where the exhaust is free of particles, by-pass line320 is configured to remove gases from the exhaust material output frommixing box 310. Controllable valve 325 is configured to selectivelypermit gases to flow into by-pass line 320. In some embodiments,controllable valve 325 is controlled to regulate a pressure of gases inby-pass line 320. By controlling the pressure of gases in by-pass line320, a pressure of gases in feedback path 322 is also controlled, whichhelps to regulate an amount of gas(es) directly from mixing box 310.

Oscillating assembly 330 is configured to vibrate the exhaust lineexiting from mixing box 310 in order to agitate particles within theexhaust line in order to reduce the risk of particle build up in theexhaust line. In some embodiments, oscillating assembly 330 is the sameas oscillating assembly 100 (FIG. 1A). Oscillating assembly 330 isconfigured to receive gas from by-pass line 320 through feedback path322. By using gas from feedback path 322 in order to generate thevibrations for agitating particles within the exhaust line, exhaustsystem 300 is able to operate more efficiently and reduce costs incomparison with other systems which rely solely on external gassupplies.

Oscillating assembly 330 is also capable of receiving gas from thebackup external gas source. In some embodiments, the oscillating elementof oscillating assembly 330 includes multiple inlets, e.g., one inletconnected to external gas source 370 and another inlet connected to thebackup gas source.

Reactor 340 is configured to chemically break down particles and fluidswhich are not flushed into first drain tank 350. In some embodiments,reactor 340 includes multiple heating elements 380 configured to rise aninternal temperature in a range from about 750 degrees Celsius to about1000 degrees Celsius. In at least one instance, in order to uniformlyincrease the internal temperature, from about 4 to about 8 heating tubesare circularly arranged in reactor 340. In some embodiments, reactorincludes a plasma-assisted element to pyrolysize particles and fluids.External gas source 370 is connected to reactor 340 to scrap particlesadhered to interior walls of heating element 380, plasma-assistedelement and reactor 340.

First drain tank 350 is configured to receive an output of the exhaustline including particles and washing fluid. Washing fluid from washingfluid inlets 345 is recycled to first drain tank 350 through one or morepipes. In some embodiments, first drain tank 350 includes a heatexchanger for cooling the washing fluid to promote precipitation ofdissolved particles from the washing fluid. First drain tank 350 isconfigured to provide a washing fluid to different portions of exhaustsystem 300 in order to help move particles through exhaust system 300.In some embodiments, the washing fluid is water. In some embodiments,the washing fluid is a solvent configured to at least partially dissolvethe particles in exhaust system 300. In some embodiments, a pressurewithin first drain tank 350 is controlled by controlling a pump 346. Insome embodiments, the pressure within washing fluid supply is controlledby controlling external gas source 370. A higher pressure in first draintank 350 causes the washing fluid to exit from washing fluid inlets 345at a higher velocity and increases a flow rate of particles withinexhaust system 300. However, using higher pressure also puts more stresson components of exhaust system 300 and increases costs of operatingexhaust system 300.

In some embodiments, first drain tank 350 includes a heating element inorder to increase a temperature of the washing fluid prior to deliveryof the cleaning fluid to washing fluid inlets 345. Increasing thetemperature of the washing fluid helps to dissolve more particles withinthe exhaust line and reduce the risk of particle build up.

Washing fluid inlets 345 are located at various points along the exhaustline. Using multiple washing fluid inlets 345 helps exhaust system 300to help boost the flow rate of particles through exhaust system 300 andreduce the risk of particle build up. In some embodiments, each fluidinlet 345 includes a nozzle. Pump 346 helps to return washing fluid tofluid inlets 345 after the washing fluid exits the exhaust line.Recycling the washing fluid helps to reduce the cost of operatingexhaust system 300. In some embodiments, an external washing fluidsupply is used to provide washing fluid to fluid inlets 345.

Second drain tank 355 is connected to first drain tank 350 by a valve.The valve is configured to open to permit washing fluid to flow fromfirst drain tank 350 to second drain tank 355 in order to transfer thewashing fluid to a reclamation process in order to help remove dissolvedparticles in the washing fluid. For example, after repeated recyclingthe washing fluid may become saturated with particles and exhibit areduced ability to assist in particle movement in the exhaust line. Atthis point, the washing fluid is transferred to a washing fluidreclamation process where dissolved particles are removed from thewashing fluid in order to help restore the ability of the washing fluidto assist with moving particles in exhaust system 300. In someembodiments, washing fluid is purified in second drain tank 355 beforerecycling back to exhaust system 300.

Return pipe 360 connects first drain tank 350 to washing exhaust system300 in order to facilitate recycling of washing fluid. Return pipe 360is also connected to circulation device 306. Circulation device 306helps to create sufficient pressure differential in return pipe 360 tomove washing fluid from exhaust system 300 to first drain tank 350.Return pipe 360 also helps to remove any gases remaining in the exhaustline downstream of by-pass line 320 by removing the gases from firstdrain tank 350. Return pipe 360 is also configured to receive anexternal supply of washing fluid. For example, when some of the washingfluid is removed to undergo a reclamation process the external supply ofwashing fluid provides additional washing fluid to return pipe 360 tohelp maintain a sufficient amount of washing fluid in exhaust system 300to move particles through the exhaust line.

External gas source 370 is configured to supply gas to reactor 340.External gas source 370 is further configured to supply additional gasto oscillating assembly 330 and/or washing fluid supply 340. In someembodiments, valves are used to control supply of the external gas tooscillating assembly 330 and reactor 340. External gas source 370 isconfigured to supply an inert gas that does not react with either thematerial of oscillating assembly 330 or reactor 340. In someembodiments, the inert gas includes nitrogen, argon or another suitableinert gas. Feedback path 322 is connected to oscillating assembly 330 inorder to provide gas to an oscillating element of oscillating assembly330.

A pressure of gases in feedback path 322 is controlled to help regulatean amount of oscillation motion by oscillating assembly 330 to agitateparticles in the exhaust line of exhaust system 300. In someembodiments, a controllable valve is controlled based on a flow rate inthe exhaust line connected to oscillating assembly 330. For example, ifthe flow rate in the exhaust line is below a predetermined threshold,then the controllable valve is opened to increase the pressure infeedback path 322 in order to create more vibration and greateragitation of particles in the exhaust line.

During operation of exhaust system 300, meters placed at variouslocations throughout exhaust system 300 monitor a flow along the exhaustline (particles or mixture of particles and washing fluid); pressure inby-pass line 320; pressure in return pipe 360 and other relevantlocations. Based on the information returned from these meters, valves,such as controllable valve 325, are opened or closed in order toefficiently remove particles from exhaust system 300. For example, ifthe flow rate detected in the exhaust line is below a predeterminedthreshold, a controller opens controllable valve 325 in order toincrease the pressure in by-pass line 320 and feedback path 322. As aresult, an amount of vibration from oscillating assembly 330 isincreased and particles in the exhaust line are more agitated. Inanother example, if the pressure in by-pass line 320 is below apredetermined threshold and controllable valve 325 is fully open, thecontroller increases a flow of gas from external gas source 370 tooscillating assembly 330.

In some embodiments, a controller connectable to exhaust system 300 isconfigured to use the measured flow rates and pressure to alert anoperator to a need for maintenance of exhaust system 300. In someembodiments, the controller is able to alert the operator that exhaustsystem 300 should undergo maintenance within a predetermined time frame.In some embodiments, the controller is able to alert the operator thatexhaust system 300 should undergo immediate maintenance. The differencesin the alerts and the time frame for maintenance is based on themeasured flow rates and pressures.

Exhaust system 300, which includes oscillating assembly 330, helps toreduce the cost of a manufacturing process. In comparison with otherexhaust systems, exhaust system 300 has a preventive maintenance cycleabout 4 times longer. For example, preventive maintenance is performedon an exhaust system which does not include oscillating assembly 330 ona monthly basis. However, preventive maintenance is only performed onexhaust system 300 every four months, in some instances. The increasedtime between preventive maintenance cycles is the result of theagitation of particles within the exhaust line which reduces the amountof particle build up. The reduced amount of preventive maintenance meansthat not only is exhaust system 300 in operation for more time; but alsomanufacturing tools connected to exhaust system 300 remain in operation.As a number of manufacturing tools connected to exhaust system 300increases, the increase in productivity also increases.

A non-limiting example is used to highlight the impact of oscillatingassembly 330. An oscillating assembly was attached to an exhaust systemsimilar to exhaust system 300. The oscillating assembly was attached ata location below the by-pass line, similar to the location indicated inFIG. 3. In some embodiments, a flow rate of 35 lpm of nitrogen gas wassupplied to an oscillating element of the oscillating assembly. Theforce generated by the flow of nitrogen gas was 1.3×10⁻⁴ kilogram-force(kgf). An amount of vibration, measured as a moving velocity in mm/s,was measured at various locations of the exhaust system. Accordingly, abearable shear force was around 3.55×10⁻⁸ thousands of pounds per squareinch (ksi). The locations are labeled 1-6 in FIG. 3. Location 1 is at amixing box; location 2 is at an exhaust line downstream of the mixingbox; location 3 is at the exhaust line downstream of location 2;location 4 is at the by-pass line; location 5 is at the exhaust lineadjacent to the oscillating assembly; and location 6 is at the exhaustline downstream of location 5. The results of the test are provided inTable 1.

TABLE 1 Location 1 2 3 4 5 6 Oscillating 0.4 0.3 0.3 0.4 0.4 0.4assembly off Oscillating 0.4 0.5 0.5 0.4 1.1 0.5 assembly on

Table 1 indicates that a vibration of the exhaust line increased nearly300% when the oscillating element of the oscillating assembly isactivated. This increased vibration in turn agitates particles withinthe exhaust line and reduces the risk of particle build up in theexhaust line.

Exhaust system 300 includes a single oscillating assembly 330. In someembodiments, exhaust system 300 includes multiple oscillating assemblies330 at various locations along the exhaust line. In some instances, anoscillating assembly is added to exhaust system 300 in response toempirical evidence that shows locations of likely particle build up. Insome embodiments, all oscillating assemblies in exhaust system 300 arecontrolled as a unit. In some embodiments, at least one oscillatingassembly in exhaust system 300 is controlled independently from at leastanother oscillating assembly in exhaust system 300.

FIG. 4 is a flow chart of a method 400 of operating an exhaust system inaccordance with some embodiments. In operation 402, an oscillatingassembly, e.g., oscillating assembly 100 or oscillating assembly 330, isactivated. In some embodiments, the oscillating assembly is activated bysupplying gas from a by-pass line to an oscillating element of theoscillating assembly. In some embodiments, the oscillating assembly isactivated by supplying gas from an external gas source to theoscillating assembly.

In operation 404, a flow rate through an exhaust line and/or a pressurein a by-pass line, e.g., by-pass line 320, is detected. In someembodiments, both the flow rate in the exhaust line and the pressure inthe by-pass line are detected. In some embodiments, only one of the flowrate in the exhaust line or the pressure in the by-pass line isdetected. In some embodiments, the flow rate through the exhaust line isdetected at multiple positions along the exhaust line. In someembodiments, a lowest flow rate from the multiple detected flow rates isused for the comparison in operation 406. In some embodiments, anaverage of the detected flow rates is used for the comparison inoperation 406.

In operation 406, the detected value is compared with a predeterminedthreshold value. If the detected value is at or above the predeterminedthreshold value, then the exhaust system is considered to be workingproperly and no adjustment is made. As indicated by the ‘Y’ arrow fromoperation 406, the detecting and comparing are repeated so long as novalue below the predetermined threshold is detected. In someembodiments, the cycle is repeated continuously. In some embodiments,the cycle is repeated periodically. If the detected value is below thepredetermined threshold value, then method 400 continues to operation408; as indicated by the ‘N’ arrow from operation 406.

In operation 408, a flow rate in the feedback path is increased or aflow from an external gas source, e.g., external gas source 370, isinitiated. In some embodiments, each time the flow rate is increasedabout 10% or 5 lpm. In some embodiments, the pressure in the feedbackpath is increased by opening a controllable valve to increase an amountof gas in the feedback path. The gas in the feedback path is fed to theoscillating element of the oscillating assembly. Increasing the pressurein the feedback path will increase the amount of oscillating movement bythe oscillating assembly. In some embodiments, the external gas flow isinitiated by opening a valve to permit gas from the external gas sourceto be fed into the oscillating element of the oscillating assembly.

In some embodiments, the pressure in the feedback path is increaseduntil the controllable valve is fully open before the external gas flowis initiated. In some embodiments, the pressure in the feedback path isincreased simultaneously with initiation of the external gas flow.

In operation 410, the flow rate through the exhaust line and/or thepressure in the feedback path is detected. In some embodiments, both theflow rate in the exhaust line and the pressure in the feedback path aredetected. In some embodiments, only one of the flow rate in the exhaustline or the pressure in the feedback path is detected. In someembodiments, the flow rate through the exhaust line is detected atmultiple positions along the exhaust line. In some embodiments, a lowestflow rate from the multiple detected flow rates is used for thecomparison in operation 412. In some embodiments, an average of thedetected flow rates is used for the comparison in operation 412.

In operation 412, the detected value is compared with the predeterminedthreshold value. The predetermined threshold value is the same foroperation 406 and operation 412. The predetermined threshold value is avalue sufficient to permit the exhaust system to effective removeparticles from a manufacturing tool to allow the manufacturing tool tooperate as designed. If the detected value is at or above thepredetermined threshold value, then the exhaust system is considered tobe working in an acceptable range and immediate maintenance isunnecessary. As indicated by the ‘Y’ arrow from operation 412, method400 proceeds to operation 414. If the detected value is below thepredetermined threshold value, immediate maintenance is recommended toprevent reduced manufacturing yield. As indicated by the ‘N’ arrow fromoperation 412, method 400 continues to operation 414. In someembodiments, operation 412 is delayed for a certain period of time inorder to permit the effect of operation 408 to register in the detectedvalues of operation 410.

In operation 414, a message is generated for scheduling maintenance forthe exhaust system. The message is transferred to an operator of theexhaust system. In some embodiments, the message provides a recommendedtime frame for performing the maintenance. In some embodiments, themessage includes both a visual and auditory component. In someembodiments, following operation 414 method 400 returns to operation404. In some embodiments, following operation 414 method 400 returns tooperation 410. In some embodiments, operation 410 limits a time framebetween subsequent messages generated for scheduling maintenance. Forexample, in some embodiments, the message for scheduling maintenance isgenerated at most once per week.

In operation 416, a message is generated for urgent maintenance for theexhaust system. The message is transferred to an operator of the exhaustsystem. In some embodiments, the message includes both a visual andauditory component.

In some embodiments, following operation 416 the exhaust system is shutdown to prevent damage to the manufacturing tool. In some embodiments,the shutdown is delayed for a certain period of time following operation416. In some embodiments, a time for shut down is included as part ofthe message.

FIG. 5 is a schematic view of a system 500 for controlling an exhaustsystem in accordance with one or more embodiments. System 500 includes ahardware processor 502 and a non-transitory, computer readable storagemedium 504 encoded with, i.e., storing, the computer program code 506,i.e., a set of executable instructions. Computer readable storage medium504 is also encoded with instructions 507 for interfacing withmanufacturing machines for producing the memory array. Processor 502 iselectrically coupled to the computer readable storage medium 504 via abus 508. The processor 502 is also electrically coupled to an I/Ointerface 510 by bus 508. A network interface 512 is also electricallyconnected to processor 502 via bus 508. Network interface 512 isconnected to a network 514, so that processor 502 and computer readablestorage medium 504 are capable of connecting to external elements vianetwork 514. The processor 502 is configured to execute the computerprogram code 506 encoded in computer readable storage medium 504 inorder to cause system 500 to be usable for performing a portion or allof the operations as described in method 400.

In some embodiments, processor 502 is a central processing unit (CPU), amulti-processor, a distributed processing system, an applicationspecific integrated circuit (ASIC), and/or a suitable processing unit.

In some embodiments, computer readable storage medium 504 is anelectronic, magnetic, optical, electromagnetic, infrared, and/or asemiconductor system (or apparatus or device). For example, computerreadable storage medium 504 includes a semiconductor or solid-statememory, a magnetic tape, a removable computer diskette, a random accessmemory (RAM), a read-only memory (ROM), a rigid magnetic disk, and/or anoptical disk. In some embodiments using optical disks, computer readablestorage medium 504 includes a compact disk-read only memory (CD-ROM), acompact disk-read/write (CD-R/W), and/or a digital video disc (DVD).

In some embodiments, storage medium 504 stores the computer program code506 configured to cause system 500 to perform method 400. In someembodiments, storage medium 504 also stores information needed forperforming a method 400 as well as information generated duringperforming the 400, such as a flow rate/pressure threshold parameter516, a valve positions parameter 518, a maintenance schedule parameter520, a flow rate/pressure parameter 522 and/or a set of executableinstructions to perform the operation of method 400.

In some embodiments, computer readable storage medium 504 storesinstructions 507 for interfacing with manufacturing machines.Instructions 507 enable processor 502 to generate instructions readableby components of the exhaust system to effectively implement method 400during a manufacturing process.

System 500 includes I/O interface 510. I/O interface 510 is coupled toexternal circuitry. In some embodiments, I/O interface 510 includes akeyboard, keypad, mouse, trackball, trackpad, and/or cursor directionkeys for communicating information and commands to processor 502.

System 500 also includes network interface 512 coupled to processor 502.Network interface 512 allows system 500 to communicate with network 514,to which one or more other computer systems are connected. Networkinterface 512 includes wireless network interfaces such as BLUETOOTH,WIFI, WIMAX, GPRS, or WCDMA; or wired network interface such asETHERNET, USB, or IEEE-1394. In some embodiments, method 400 isimplemented in two or more systems 500, and information such as memorytype, memory array layout, I/O voltage, I/O pin location and charge pumpare exchanged between different systems 500 via network 514.

During operation, processor 502 executes a set of instructions tocompare flow rate/pressure parameter 522 with flow rate/pressurethreshold parameter 516. Based on the results of the comparison, process502 is configured to execute instructions transmitting control signalsto valves of an exhaust system for controlling valve positions andupdating valve positions parameter 518. Processor 502 is also configuredto generate messages related to the maintenance schedule based onmaintenance schedule parameter 520.

An aspect of this description relates to a method of using an exhaustsystem. The method includes activating an oscillating assembly connectedto an exhaust line, wherein the oscillating assembly is configured tovibrate the exhaust line. The method further includes measuring a valueindicating a flow of particles through the exhaust line. The methodfurther includes comparing the value with a predetermined thresholdvalue. The method further includes increasing a rate of vibration of theexhaust line in response to the value being below the predeterminedthreshold value. In some embodiments, activating the oscillatingassembly includes agitating particles adhered to interior walls of theexhaust line. In some embodiments, increasing the rate of vibrationincludes increasing the pressure in an external gas source. In someembodiments, the method further includes detecting a flow rate throughthe exhaust line. In some embodiments, the method further includesgenerating a message for scheduling maintenance in response to thedetected flow rate being at or above a flow rate threshold; andgenerating a message for urgent maintenance in response to the detectedflow rate being below the flow rate threshold. In some embodiments, themethod further includes detecting a pressure in a by-pass line, whereinthe by-pass line is connected to the exhaust line. In some embodiments,the method further includes generating a message for schedulingmaintenance in response to the detected pressure satisfying a pressurethreshold; and generating a message for urgent maintenance in responseto the detected pressure failing to satisfy the pressure threshold.

An aspect of this description relates to a method of using anoscillating assembly. The method includes attaching the oscillatingassembly to a line configured to transport particles. The method furtherincludes receiving a flow at an inlet of a chamber of the oscillatingassembly. The method further includes discharging the flow at an outletof the chamber. The method further includes rotating a moveable elementwithin the chamber using the flow. The method further includes modifyinga flow rate of the flow to adjust a rotation speed of the moveableelement within the chamber. In some embodiments, attaching theoscillating assembly to the line includes removably attaching theoscillating assembly to the line. In some embodiments, attaching theoscillating assembly to the line includes permanently attaching theoscillating assembly to the line. In some embodiments, modifying theflow rate includes modifying the flow rate based on a detected flow ofparticles through the line. In some embodiments, modifying the flow rateincludes modifying the flow rate using an external gas source separatefrom the line.

An aspect of this description relates to a method of using an exhaustsystem. The method includes activating a first oscillating assemblyconnected to an exhaust line at a first location, wherein the firstoscillating assembly is configured to vibrate the exhaust line. Themethod further includes measuring a flow of particles through theexhaust line. The method further includes increasing a rate of vibrationof the exhaust line in response to the flow of particles being below thepredetermined threshold value. The method further includes detecting aflow rate in the exhaust line in response to the flow of particles beingbelow the predetermined threshold value. In some embodiments, the methodfurther includes activating a second oscillating assembly connected tothe exhaust line at a second location different from the first location.In some embodiments, the method further includes generating a messagefor scheduling maintenance in response to the detected flow rate beingat or above a flow rate threshold; and generating a message for urgentmaintenance in response to the detected flow rate being below the flowrate threshold. In some embodiments, activating the first oscillatingassembly includes receiving a gas flow at the first oscillatingassembly; and rotating a moveable element within the first oscillatingassembly using the gas flow. In some embodiments, the method furtherincludes detecting a pressure in a by-pass line, wherein the by-passline is connected to the exhaust line. In some embodiments, the methodfurther includes generating a message for scheduling maintenance inresponse to the detected pressure satisfying a pressure threshold; andgenerating a message for urgent maintenance in response to the detectedpressure failing to satisfy the pressure threshold. In some embodiments,the method further includes permanently attaching the first oscillatingassembly to the exhaust line at the first location. In some embodiments,the method further includes removably attaching the first oscillatingassembly to the exhaust line at the first location.

While the disclosure has been described by way of example and in termsof the above embodiments, it is to be understood that the invention isnot limited to the disclosed embodiments. To the contrary, it isintended to cover various modifications and similar arrangements (aswould be apparent to those skilled in the art). Therefore, the scope ofthe appended claims should be accorded the broadest interpretation toencompass all such modifications and similar arrangements.

What is claimed is:
 1. A method of using an exhaust system configuredfor production of semiconductors and componentry thereof, the methodcomprising: activating an oscillating assembly connected to an exhaustline, wherein the oscillating assembly is configured to vibrate theexhaust line; measuring a value indicating a flow of particles throughthe exhaust line; comparing the value with a predetermined thresholdvalue; and increasing a rate of vibration of the exhaust line inresponse to the value being below the predetermined threshold value. 2.The method of claim 1, wherein activating the oscillating assemblycomprises agitating particles adhered to interior walls of the exhaustline.
 3. The method of claim 1, wherein increasing the rate of vibrationcomprises increasing pressure in an external gas source.
 4. The methodof claim 1, further comprising detecting a flow rate through the exhaustline.
 5. The method of claim 4, further comprising: generating a messagefor scheduling maintenance in response to the detected flow rate beingat or above a flow rate threshold; and generating a message for urgentmaintenance in response to the detected flow rate being below the flowrate threshold.
 6. The method of claim 1, further comprising detecting apressure in a by-pass line, wherein the by-pass line is connected to theexhaust line.
 7. The method of claim 6, further comprising: generating amessage for scheduling maintenance in response to the detected pressuresatisfying a pressure threshold; and generating a message for urgentmaintenance in response to the detected pressure failing to satisfy thepressure threshold.
 8. A method of using an oscillating assemblyconfigured for production of semiconductors and componentry thereof, themethod comprising: attaching the oscillating assembly to a lineconfigured to transport particles; receiving a flow at an inlet of achamber of the oscillating assembly; discharging the flow at an outletof the chamber; rotating a moveable element within the chamber using theflow; and modifying a flow rate of the flow to adjust a rotation speedof the moveable element within the chamber.
 9. The method of claim 8,wherein attaching the oscillating assembly to the line comprisesremovably attaching the oscillating assembly to the line.
 10. The methodof claim 8, wherein attaching the oscillating assembly to the linecomprises permanently attaching the oscillating assembly to the line.11. The method of claim 8, wherein modifying the flow rate comprisesmodifying the flow rate based on a detected flow of particles throughthe line.
 12. The method of claim 8, wherein modifying the flow ratecomprises modifying the flow rate using an external gas source separatefrom the line.
 13. A method of using an exhaust system configured forproduction of semiconductors and componentry thereof, the methodcomprising: activating a first oscillating assembly connected to anexhaust line at a first location, wherein the first oscillating assemblyis configured to vibrate the exhaust line; measuring a flow of particlesthrough the exhaust line; increasing a rate of vibration of the exhaustline in response to the flow of particles being below a predeterminedthreshold value; and detecting a flow rate in the exhaust line inresponse to the flow of particles being below the predeterminedthreshold value.
 14. The method of claim 13, further comprisingactivating a second oscillating assembly connected to the exhaust lineat a second location different from the first location.
 15. The methodof claim 13, further comprising: generating a message for schedulingmaintenance in response to the detected flow rate being at or above aflow rate threshold; and generating a message for urgent maintenance inresponse to the detected flow rate being below the flow rate threshold.16. The method of claim 13, wherein activating the first oscillatingassembly comprises: receiving a gas flow at the first oscillatingassembly; and rotating a moveable element within the first oscillatingassembly using the gas flow.
 17. The method of claim 13, furthercomprising detecting a pressure in a by-pass line, wherein the by-passline is connected to the exhaust line.
 18. The method of claim 17,further comprising: generating a message for scheduling maintenance inresponse to the detected pressure satisfying a pressure threshold; andgenerating a message for urgent maintenance in response to the detectedpressure failing to satisfy the pressure threshold.
 19. The method ofclaim 13, further comprising permanently attaching the first oscillatingassembly to the exhaust line at the first location.
 20. The method ofclaim 13, further comprising removably attaching the first oscillatingassembly to the exhaust line at the first location.